Journal of Physical Chemistry A, Vol.119, No.42, 10475-10480, 2015
A Study of the Monohydrate and Dihydrate Complexes of Perfluoropropionic Acid Using Chirped-Pulse Fourier Transform Microwave (CP-FTMW) Spectroscopy
This work reports the first known spectroscopic observation of the monohydrate and dihydrate complexes of perfluoropropionic acid (PFPA). The spectra have been observed using a chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer in the 7750 to 14250 MHz region. The structures of the species have been confirmed with the aid of ab initio quantum chemical calculations. Rotational constants A, B, and C have been determined and reported for both species along with centrifugal distortion constants Delta(J), Delta(JK), Delta(K), delta(J), delta(K) for H2O-PFPA and Delta(J), Delta(JK), delta(J) for (H2O)(2)-PFPA. Effects due to large amplitude motions were not observable in these experiments. Structures of the complexes have been determined using a combination of experimental second moment values and ab initio results. The complexation of the -OH of one or two water molecules has been found to occur in the plane of the carboxylic acid group forming a six- or eight-member ring.